I'm sensing a yu gi oh reference.
*In the voice of Joey Wheeler* I summon ... Buster Blader, and equip him with KUNAI WITH CHAIN!
Lol.
Ya, I was thinking exactly the same thing myself when I first saw the topic.
I like this card but I find that the function is already in the game.

I think being able to disable the opponents creature is the main difference here. PU gives you an exact copy but the original stays where it is. This one actually steals it away.
So this card serves a quite different role.
Having this as a creatuer also helps mitigate an effective instant kill like effect because you would have to wait 1 turn before you can use the ability.
Finally, it is well priced so it would be difficult to abuse via fractal or mitosis.
I think its pretty well put together
On a different note, could you target your own creatures with this card? I.e. if someone popped AM and Liquid Shadow on my Colossal dragon, could I use this to negate its attack? That would most definitely set it apart from PU.